Cartridge for m16/ar15 rifles

ABSTRACT

One embodiment of the invention sets forth a cartridge design that includes a bullet having a larger diameter than the 0.224 inch bullet currently included in the 223 Remington or 5.56 mm NATO cartridge and a case that has substantially the same base diameter as the case currently included in the 223 Remington or the 5.56 mm NATO cartridge. The overall length of the disclosed cartridge is substantially similar to the overall length as the 223 Remington or the 5.56 mm NATO cartridge.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Pat. App. Nos.60/804,186 (Atty. Dock. No. KRAMER/001 (now KRMR/0002L)), filed Jun. 8,2006; 60/807,448 (Atty. Dock. No. KRAMER/002 (now KRMR/0003L)) filedJul. 14, 2006; 60/807,454 (Atty. Dock. No. KRAMER/003 (now KRMR/0004L)),filed Jul. 14, 2006; 60/807,459 (Atty. Dock. No. KRAMER/004 (nowKRMR/0005L)), filed Jul. 14, 2006; 60/807,464 (Atty. Dock. No.KRAMER/005 (now KRMR/0006L)), filed Jul. 14, 2006; and 60/807,465 (Atty.Dock. No. KRAMER/006 (now KRMR/0007L)) filed Jul. 14, 2006 which arehereby incorporated by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relates generally to rifles andmore specifically to a new cartridge design for M16/AR15 rifles.

2. Description of the Related Art

The current cartridge used for the M16/AR15 rifles is the 223 Remington(the civilian designation) or the 5.56 mm (×45 mm) NATO (the militarydesignation). The overall performance of this cartridge has proven quiteunsatisfactory, especially in combat applications, because of the small224 caliber bullet used in the cartridge. In particular, the 224 caliberbullets tend to have poor terminal performance, where an insufficientamount of energy is transferred to the target upon impact, and they tendto loose energy rapidly after firing, which can cause the bullets todeflect off the intended target. Over the years, the weight of the 224caliber bullet has been increased from fifty-five grain to sixty-twograin to seventy-seven grain in attempts to improve performance. Todate, however, performance remains at issue.

Another attempted solution to the above problem introduces a newcartridge design commonly referred to as the 6.8 mm special purposecartridge (SPC). This cartridge includes a larger 6.8 mm or 277 caliberbullet that weighs one-hundred and fifteen grains. Although the largerbullet provides better terminal performance, a larger case diameter isrequired to accommodate the extra gun powder needed to propel theheavier bullet. Since the larger case cannot be used with currentM16/AR15 rifle magazines, implementing this solution would requiremodifying or replacing all existing rifle magazines. In addition, a boltwith a larger face would be needed to accept the case, which wouldrequire replacing all existing rifle bolts. Further, loadingaccessories, such as bandoleers and stripper clips are also incompatiblewith the SPC cartridge. In sum, the modifications to existing M16/AR15rifles that would be required to effectively implement the 6.8 mm SPCmake the 6.8 mm SPC an impractical solution to the above problem.

As the foregoing illustrates, what is needed in the art is a costeffective, higher performance cartridge for M16/AR15 and similar rifles.

SUMMARY OF THE INVENTION

One embodiment of the invention sets forth a cartridge design thatincludes a bullet having a larger diameter than the 0.224 inch bulletcurrently included in the 223 Remington or 5.56 mm NATO cartridge and acase that has substantially the same base diameter as the case currentlyincluded in the 223 Remington or the 5.56 mm NATO cartridge. The overalllength of the disclosed cartridge is substantially similar to theoverall length as the 223 Remington or the 5.56 mm NATO cartridge.

One advantage of the disclosed cartridge design is that a larger bulletis used, thereby increasing terminal performance. Further, the basediameter of the case and overall cartridge length can be accommodated bycurrent M16/AR15 rifles without expensive modification.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A illustrates a template for cartridges for an M16/AR15 rifle,according to embodiments of the present invention.

FIG. 1B is a table illustrating dimensions for cartridges illustrated inFIG. 1A for an M16/AR15 rifle, according to embodiments of the presentinvention.

FIG. 2A illustrates a template for reamers for manufacturing barrels foran M16/AR15 rifle so that the rifle will accommodate the cartridgesillustrated in FIG. 1, according to embodiments of the present invention

FIG. 2B is a table illustrating dimensions for reamers illustrated inFIG. 2A for an M16/AR15 rifle, according to embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1A illustrates a template for cartridges for an M16/AR15 rifle,according to embodiments of the present invention. FIG. 1B is a tableillustrating dimensions for cartridges illustrated in FIG. 1A for anM16/AR15 rifle, according to embodiments of the present invention.Abbreviations not illustrated in FIG. 1A are neck thickness NT andcartridge length CL.

As shown, six bullets 102, ranging from 6 mm to 7.62 mm in diameter, areused in combination with six respective cases 104 that have a basediameter, H, substantially similar or identical to the base diameter ofthe case included in the 223 Remington or the 5.56 mm NATO cartridge.Alternatively, any bullet having a larger diameter than the 0.224 inchdiameter bullet may be used. The bullets 102 may be made from a metal,such as lead and jacketed with a second metal, such as copper, an alloythereof, or steel. The bullets 102 may have hollow or solid points. Thecases 104 may be made from a metal, such as brass. The top part of thecase 104 is configured to accommodate the relatively wider diameter ofthe bullets 102. The overall length CL of the cartridge 100, when thebullet 102 and the case 104 are assembled, is substantially similar oridentical to overall length of the 223 Remington or the 5.56 mm NATO.

Since both the base diameter of the cases 104 and the overall length ofthe cartridges 100 are substantially similar or identical to what isfound in the 223 Remington or the 5.56 mm NATO cartridge, the cartridges100 may be used with M16/AR15 rifles or any rifle that accepts 223Remington or 5.56 mm NATO ammunition without expensive modification tothose rifles. The cartridges 100 are compatible with existing bolts. Thecartridges 100 are also compatible with existing magazines (with no orslight modification) and existing loading accessories. Further, thelarger bullet 102 provides better terminal performance than the smaller0.224 inch bullet currently used with M16/AR15 rifles. Further benefits,such as increased barrel life and decreased firing rate may also berealized by the cartridges 100. Thus, the disclosed cartridge designsare a substantial improvement over prior art cartridge designs.

The following is a non-exclusive list of gun powders that may be usedwith the disclosed cartridge 100: Accurate Arms 2460, Hodgdon H4895,Hodgdon Varget, Hodgdon H335, IMR 4064, Reloader 15 and VV N 133. Highperformance powders such as these may be used to compensate for thelarger bullet 102 included in cartridges 100 to achieve additionalperformance benefits.

FIG. 2A illustrates a template for reamers for manufacturing barrels foran M16/AR15 rifle so that the rifle will accommodate the cartridgesillustrated in FIG. 1, according to embodiments of the presentinvention. FIG. 2B is a table illustrating dimensions for reamersillustrated in FIG. 2A for an M16/AR15 rifle, according to embodimentsof the present invention. Abbreviations not illustrated in FIG. 2A areshank length SHLG, Pilot Length PLLG, OAL Blank OLBK, Pilot Size PLSZ,Bore Size BORE, Groove Size GRV, Basic Brass BBRASS, Body TPI BDTPI,Neck TPI NKTPI, and Throat TPI THTPI.

The above description and figures illustrate various embodiments of thepresent invention along with examples of how aspects of the presentinvention may be implemented. The above examples, embodiments, anddrawings should not be deemed to be the only embodiments, and arepresented to illustrate the flexibility and advantages of the presentinvention. For example, persons skilled in the art will appreciate thatany cartridge design having an overall length and case outer diameterthat are substantially similar to those of the 223 Remington or the 5.56mm NATO cartridge, where the included bullet has a diameter greater thanthe 0.224 inch, falls within the scope of the present invention. Thecartridges 100 shown in FIGS. 1A and 1B are simply examples of thepresent invention. Further, the cartridges 100 may be used with anyrifle that accepts 223 Remington or 5.56 mm NATO ammunition, includingbolt-action rifles and other gas operated rifles.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A rifle cartridge, comprising: a bullet with a diameter greater than6.5 mm; and a case with a base diameter substantially similar to a basediameter of the 223 Remington or the 5.56 mm NATO cartridge, wherein: alength of the rifle cartridge is substantially similar to a length the223 Remington or the 5.56 mm NATO cartridge the cartridge is compatiblewith a standard bolt of an M16 or AR15 rifle.
 2. The cartridge of claim1, wherein the bullet diameter is greater than or equal to 6.8 mm andless than or equal to 7.62 mm.
 3. The cartridge of claim 2, wherein thebase diameter is identical to the base diameter of the 223 Remington orthe 5.56 mm NATO cartridge.
 4. The cartridge of claim 2, wherein thelength of the cartridge is identical to the length of the 223 Remingtonor the 5.56 mm NATO cartridge.
 5. The cartridge of claim 1, wherein thebullet has a hollow point.
 6. The cartridge of claim 1, wherein thebullet is made from lead and jacketed with a copper alloy and the caseis made from brass.
 7. A method of retrofitting an assault rifle thataccepts 0.223 Remington or 5.56 mm NATO cartridges, comprising: removinga barrel of the assault rifle; and attaching a barrel configured toaccept the cartridge of claim
 1. 8. The method of claim 7, wherein themethod consists essentially of: removing a barrel of the assault rifle;and attaching a barrel configured to accept the cartridge of claim
 1. 9.The method of claim 7, further comprising: loading cartridges of claim 1into an existing magazine of the assault rifle; and firing the assaultrifle using an existing bolt of the assault rifle.
 10. The cartridge ofclaim 1, further comprising a high performance gun powder operable tocompensate for the larger bullet.